1. Field of the Invention
The present invention relates to a liquid crystal display (LCD), and more particularly, to an LCD having excellent lateral visibility without light leakage.
2. Description of the Related Art
A liquid crystal display (LCD) is one of the most widely used flat panel displays. An LCD includes two panels provided with field-generating electrodes such as pixel electrodes and a common electrode and a liquid crystal (LC) layer interposed therebetween. The LCD displays images by applying voltages to the field-generating electrodes to generate an electric field in the LC layer. The applied electric field determines the orientations of LC molecules in the LC layer to adjust the polarization of incident light.
Among the LCDs, a vertically aligned (VA) LCD, in which LC molecules are aligned such that the long axes of the LC molecules are perpendicular to the plates in the absence of an electric field, offers a high contrast ratio and a wide reference viewing angle. The wide viewing angle of the VA LCD is achieved by forming cutouts in and protrusions on the field-generating electrodes.
However, images displayed by a patterned vertically aligned (PVA) LCD equipped with gaps become brighter nearer to the lateral sides of the PVA LCD, thereby decreasing lateral visibility. In order to improve lateral visibility of an LCD, a variety of methods of dividing a pixel electrode into a pair of sub-pixel electrodes and driving the sub-pixel electrodes using different thin film transistors (TFTs) so that the sub-pixel electrodes can be supplied with different voltages have been suggested.
In order to drive two TFTs, two gate lines must be provided for each pixel. In this case, one of the two gate lines is disposed so as to cross the corresponding pixel. However, when a gate line that is disposed so as to cross a pixel is exposed through a gap, part of a liquid crystal corresponding to the exposed portion of the gate line is affected by an electric field generated by the gate line. In general, a gate-off voltage applied to a gate line is much lower than a voltage applied to other parts of a pixel region. Thus, a portion of a liquid crystal layer corresponding to an exposed gate line may have a different alignment angle from other portions of the liquid crystal and may thus appear to leak light at an early stage of the driving of an LCD.